Fix ioctl_tree_execute() ret type and initialization

[hdeller]

The umockdev-vala testcase randomly fails on some platforms (hppa, sparc64, powerpc, see:[1][2][3]) because the ioctl() testcase checks the return value pointed to by "ret" in ioctl_tree_execute() which might have stale data as it wasn't initialized.

Fix it by properly initializing the return code.
Additionally force all code paths to provide a valid return code address.

Tested on hppa-linux and armhf-linux.

[1] https://buildd.debian.org/status/fetch.php?pkg=umockdev&arch=hppa&ver=0.19.0-1&stamp=1735373270&raw=0
[2] https://buildd.debian.org/status/fetch.php?pkg=umockdev&arch=powerpc&ver=0.19.0-1&stamp=1735375553&raw=0
[3] https://buildd.debian.org/status/fetch.php?pkg=umockdev&arch=sparc64&ver=0.19.0-1&stamp=1735380455&raw=0

[martinpitt]

Thanks for spotting this! Do you want to fix it up yourself, or want me to take over?

[hdeller]

Martin, I'm happy that you take over and fix it the way you want it.
Thanks!

[martinpitt]

Thanks @hdeller ! I fixed the points above, and also cleaned up the commit message a bit.

[martinpitt]

Thanks @hdeller ! I fixed the points above, and also cleaned up the commit message a bit. Before I do a new release, let's discuss/sort out #262

[hdeller]

problem still happens on hppa build:
DEBUG: umockdev.vala:1414: parsing device description for /devices/mycam
DEBUG: umockdev.vala:1492: creating device /devices/mycam (subsystem usb)
DEBUG: umockdev.vala:1538: create_node_for_device: creating file device /tmp/umockdev.SLZ0Z2/dev/001
DEBUG: umockdev.vala:832: umockdev_testbed_uevent: sending uevent add for device /sys/devices/mycam
**
ERROR:../tests/test-umockdev-vala.vala:284:t_usbfs_ioctl_static: assertion failed (ioctl (fd2, TIOCSBRK, 0) == 0): (-1 == 0)
not ok /umockdev-testbed-vala/usbfs_ioctl_static - ERROR:../tests/test-umockdev-vala.vala:284:t_usbfs_ioctl_static: assertion failed (ioctl (fd2, TIOCSBRK, 0) == 0): (-1 == 0)

[hdeller]

With this patch testcase succeeds on hppa and s390x:

diff --git a/tests/test-umockdev-vala.vala b/tests/test-umockdev-vala.vala
index 0d4add0..9cd88e2 100644
--- a/tests/test-umockdev-vala.vala
+++ b/tests/test-umockdev-vala.vala
@@ -281,8 +281,8 @@ E: SUBSYSTEM=usb
   // unknown ioctls do work on non-emulated devices
   int fd2 = Posix.open ("/dev/tty", Posix.O_RDWR, 0);
   if (fd2 > 0) {
-      assert_cmpint (Posix.ioctl (fd2, Ioctl.TIOCSBRK, 0), CompareOperator.EQ, 0);
-      assert_cmpint (Posix.errno, CompareOperator.EQ, 0);
+      assert_cmpint (Posix.ioctl (fd2, Ioctl.TIOCSBRK, 0), CompareOperator.EQ, -1);
+      assert_cmpint (Posix.errno, CompareOperator.EQ, Posix.ENOTTY);
       Posix.close (fd2);
   }

Update:
The test is flaky.... Sometimes the code path isn't executed on s390x.
Posix.open ("/dev/tty") often returns -1 on s390x, which is why the part inside the braces is never executed.
Sometimes it returns file-descriptor 19 and then the check in the braces fail.
Seems to be related to how many tests run in parallel.

UPDATE:
I opened pull request #263 to follow up on this...